iscernible, marked where great liners were standing in for the
distant metropolis. To the north, far away, showed a sail or two, of
fishing craft or coastwise schooner.

An exclamation escaped Frank and he leaned sidewise, gripping Jack by
the arm and pointing with his free hand. But Jack had a radio receiver
clamped on his head and was frowning. He glanced only hastily in the
direction indicated by Frank, then shut his eyes as if in an effort at
concentration.

Frank continued to gaze, then bent down and unlashed a pair of
binoculars from a pocket in the pit and, putting the glasses to his
eyes, threw back his head and began scanning the sky. After staring
long minutes, he hastily put aside the glasses, lifted the radio
transmitter strapped to his chest and spoke in it to Bob:

"Bob, there's a plane overhead. So high you can't see it with the
naked eye. But I spotted it before it rose too high, and followed it
with the glasses. The fellow's up where the sun plays tricks with your
eyesight. And, Bob, I've got a hunch he's watching us. There's
Starfish Cove below us now. Keep right on flying. Don't turn inland."

Bob nodded, and the plane continued its way westward offshore. Frank
again took up the glasses and searched the sky, gradually increasing
the focal radius. An exclamation from Frank and a hurried request in
the transmitter presently reached Bob's ears:

"Shut her off, Bob, and let's land on the water. Quick. I'll explain
in a minute."

Obediently, big Bob shut off the engine, and the plane coasted on a
long slant to a safe landing some hundreds of yards out from the
sandy, deserted shore.

Bob and Jack snatched the headpieces off, and turned inquiringly to
their chum.

"Here," cried Frank, pressing the glasses into Bob's hands. "Take a
look. That plane is landing way back there, and I believe it is at
Starfish Cove."

Bob was too late to see if the situation was as Frank described,
however. Putting up the glasses, he turned to his chum.

"Tell us about it," he said.

"Yes," said Jack. "I heard what you told Bob, but not having the
glasses I couldn't see. At first, when you punched me, besides, I was
thinking over that business of the strange interference with our radio
and wondering what it could be. So I didn't get to see. I suppose you
were trying to point out this other plane to me then?"

Frank nodded.

"Yes," he said, "it was just a tiny speck at that time, but I could
see it with the nake